全文获取类型
收费全文 | 22466篇 |
免费 | 1876篇 |
国内免费 | 33篇 |
学科分类
医药卫生 | 24375篇 |
出版年
2024年 | 37篇 |
2023年 | 245篇 |
2022年 | 387篇 |
2021年 | 832篇 |
2020年 | 522篇 |
2019年 | 737篇 |
2018年 | 808篇 |
2017年 | 620篇 |
2016年 | 700篇 |
2015年 | 699篇 |
2014年 | 863篇 |
2013年 | 1307篇 |
2012年 | 1896篇 |
2011年 | 1825篇 |
2010年 | 946篇 |
2009年 | 816篇 |
2008年 | 1321篇 |
2007年 | 1379篇 |
2006年 | 1254篇 |
2005年 | 1186篇 |
2004年 | 1097篇 |
2003年 | 905篇 |
2002年 | 891篇 |
2001年 | 209篇 |
2000年 | 211篇 |
1999年 | 219篇 |
1998年 | 175篇 |
1997年 | 145篇 |
1996年 | 124篇 |
1995年 | 119篇 |
1994年 | 96篇 |
1993年 | 90篇 |
1992年 | 131篇 |
1991年 | 107篇 |
1990年 | 104篇 |
1989年 | 97篇 |
1988年 | 115篇 |
1987年 | 113篇 |
1986年 | 99篇 |
1985年 | 88篇 |
1984年 | 105篇 |
1983年 | 75篇 |
1982年 | 63篇 |
1981年 | 62篇 |
1980年 | 41篇 |
1979年 | 47篇 |
1978年 | 49篇 |
1975年 | 33篇 |
1973年 | 31篇 |
1970年 | 34篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
12.
Surgery alone has long been the standard treatment for patients with operable non-small-cell lung cancer (NSCLC). However, despite complete resection, 5-year survival rates have been disappointing, with about 50% of patients eventually suffering relapse and death from disease. Randomized trials conducted in the 1980s hinted at a survival benefit for postoperative cisplatin-based regimens, but they were underpowered. A meta-analysis published in 1995 found a nonsignificant 13% reduction in the risk of death associated with cisplatin-based chemotherapy, with an increase of survival of 5% at 5 years. This led to renewed interest in adjuvant chemotherapy in resected NSCLC. Thousands of patients have been included in a new generation of randomized trials in the last 10 years. Most of these recent studies have now been reported and several have demonstrated a clear survival advantage for patients treated with platin-based adjuvant therapy. These results also suggest a greater benefit with modern two-drug regimens. In view of the most recent data, postoperative platin-based chemotherapy can now be considered the standard of care for completely resected NSCLC patients with good performance status. 相似文献
13.
14.
Susan W. Muir Katherine Berg Bert Chesworth Neil Klar Mark Speechley 《Journal of clinical epidemiology》2010,63(4):389-406
ObjectivesTo evaluate and summarize the evidence linking balance impairment as a risk factor for falls in community-dwelling older adults.Study Design and SettingSystematic review and meta-analysis. English language articles in MEDLINE, EMBASE, CINAHL (1988–2009), under keywords of accidental falls, aged, risk factors, and hip, radius, ulna, and humerus fractures; and bibliographies of retrieved articles. Community-dwelling older adults in a prospective study, at least 1-year duration, age more than 60 years, and samples not specific to a single disease-defined population were included. Sample size, inclusion/exclusion criteria, demographics, clinical balance measurement scale, type of fall outcome, method of fall ascertainment, length of follow-up, and odds ratio (OR) or risk ratio (RR) were extracted. Studies must have reported adjustment for confounders. Random effects meta-analysis to generate summary risk estimate was used. A priori evaluation of sources of heterogeneity was performed.ResultsTwenty-three studies met the selection criteria. A single summary measure could not be calculated because of the nonequivalence of the OR and RR, producing an overall fall risk of RR of 1.42 (1.08, 1.85) and OR of 1.98 (1.60, 2.46).ConclusionsBalance impairment imparts a moderate increase on fall risk in community-dwelling older adults. The type of fall outcome, the length of follow-up, and the balance measurement tool impact the magnitude of the association. Specific balance measurement scales were identified with associations for an increased fall risk, but further research is required to refine recommendations for their use in clinical practice. 相似文献
15.
16.
17.
18.
19.
20.